%0 Journal Article
%T a(1)(1420) peak as the pi f(0)(980) decay mode of the a(1)(1260)
%A Aceti, F.
%A Dai, L. R.
%A Oset, E.
%J Physical Review D
%D 2016
%V 94
%N 9
%I Amer Physical Soc
%@ 2470-0010
%G English
%F Aceti_etal2016
%O WOS:000388824300007
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=2912), last updated on Thu, 02 Feb 2017 09:20:23 +0000
%X We study the decay mode of the a(1)(1260) into a pi(+) in p wave and the f(0)(980) that decays into pi(+)pi(-) in s wave. The mechanism proceeds via a triangular mechanism where the a(1)(1260) decays into K*K-, the K* decays to an external pi(+) and an internal K that fuses with the (K) over bar producing the f(0)(980) resonance. The mechanism develops a singularity at a mass of the a(1)(1260) around 1420 MeV, producing a peak in the cross section of the pp reaction, used to generate the mesonic final state, which provides a natural explanation of all the features observed in the COMPASS experiment, where a peak observed at this energy is tentatively associated to a new resonance called a(1)(1420). On the other hand, the triangular singularity studied here gives rise to a remarkable feature, where a peak is seen for a certain decay channel of a resonance at an energy about 200 MeV higher than its nominal mass.
%R 10.1103/PhysRevD.94.096015
%U http://arxiv.org/abs/1606.06893
%U https://doi.org/10.1103/PhysRevD.94.096015
%P 096015-9pp